This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Phospho-creatine (PCr) and Adenosine tri-phosphate (ATP) are the major energy sources/reservoirs in the biological system. The concentration of ATP and PCr is varied in the different organs. The ATP concentration in brain, heart and muscle is ~3-4mM, ~6mM and ~10mM, respectively. On the other hand PCr which is a major source of energy reservoir present around 5-6mM in brain, 10mM in heart and around 33.5mM in muscles. Alternations of these energy-rich compounds have been reported in various disease conditions including tumors, heart infarction and muscular disorders. 31P MRS has been widely used to detect the signal from these metabolites. Phosphorous imaging of PCr has been previously reported utilizing MT effects between Pi and PCr. Here, for the first time we report the chemical exchange saturation transfer (CEST) effect from PCr and ATP in-vitro on phantoms by exploiting their labile amine protons (-NH2) as well as a PCr MRI CEST map from resting calf muscle.